AXT turbo installation

[Spore]

Hi All-

I have a '81 BJ42 with a 3B and an in-line injection pump. I have a used AXT turbo presently installed. AXT themselves told me that adjustments must be made to the governor, idle, and fuel volume. They never responded when I asked for a copy of installation instructions. Idle and volume are easy enough, but I would like to know what must be done to the governor. It makes sense that a vacuum/pressure differentially controlled device such as that would be greatly affected by the introduction of 10psi boost!

Being an inline pump, it has no compensator like the rotory pumps have. There are driveability issues, such as terrible mileage (18mpg highway) and a near lack of power up any incline, especially in higher gears.

So my question is this: does anyone have a copy of the installation intructions that they would be willing to scan, email me, whatever? Or any suggestions/opinions?

I'd be eternally grateful!

 

[cruiser_guy]

You're having issues with lack of power and the AXT kit? I just bolted mine on and it made a huge improvement about 5 years ago. I did not adjust anything on my engine, no fuel, no idle and no governor adjustments.

 

[MOTERRA]

might be best to try slight adjustment (towards lean) till you like how it runs..and don't bother with the governor...sounds like you have too much fuel and it's going out the tail pipe and giving you a "bogging" when you load it up.. if you never ran it without the turbo then you won't know where the original fuel/idle settings where...so you could just be way over fueling it.????

my two pennies hope it works out fer ya

 

[Tapage]

If I remeber well the Turbo Glide instructions, advice for a 1/4 turn up the fuel @ IP sure the turbo it's pre setted to 8 - 9 PSI ( wastegated ). The AXT instrucions advice for a Pyro gauge for proper tune, if you don't have it keep the facotry settings ..

At this point and plus you already vary the factory IP settings your best way it's get a Pyro ..

 

[cruiser_guy]

Yes, as "Tapage" says do NOT make adjustments without a pyrometer. You'd be asking for trouble otherwise.

 

[-MaTTi-]

AXT themselves told me that adjustments must be made to the governor, idle, and fuel volume.

Do anyone remember what that includes?

 

[brownbear]

ooh resurection of a 14 year old thread.

The fueling screw, which they must be describing as volume, set the power. Too much fuel, too much heat and black smoke. Too little fuel and no power...

The only govenor adjustment i am aware of is adjusting the timing of the fuel pump. I've never touched mine. There is no reason why with a turbo you would need to adjust this off the regular settings. The FSM is the source on how to adjust this.

As for the volume screw, you absolutely need a pyro gauge to ensure you do not over temp.

 

[-MaTTi-]

There is no reason why with a turbo you would need to adjust this off the regular settings. The FSM is the source on how to adjust this.

There is a reason, because of the fuel need is no more linear with a turbo. I would like to know how AXT is determined that, the FSM I have read.

 

[-MaTTi-]

Found something:

The kit does work well with the in-line pump, however sometimes the vent side of the venturi plate will need additional bleed-off, to stop power surging, but this is very easy to sort out.

You can expect 45% more torque and power over standard, running at 8PSI boost pressure.
The kit comes bench assembled, with basic drawings and instructions for easy installation.
On your specific vehicle, you may need to alter the exhaust system slightly, but this should be straight-forward, just cutting and welding.

The kit includes the tuning diagrams.
Most pumps are fine, especially when they have been serviced. Generally only older pumps suffering from soft diaphragms and springs in the rear section of the pump are effected, and the additional bleed off is basically just to compensate for “worn” components only. Only effected pumps will have the “jerkiness”, however with the bleed off, this problem is resolved.